Geothermal: Tapping Earth's abundant energy

By David Suzuki with contributions from David Suzuki Foundation Senior Editor Ian Hanington.

In the midst of controversy over B.C.’s Peace River Site C dam project, the Canadian Geothermal Energy Association released a study showing the province could get the same amount of energy more affordably from geothermal sources for about half the construction costs. Unlike Site C, geothermal wouldn’t require massive transmission upgrades, would be less environmentally disruptive and would create more jobs throughout the province rather than just in one area.

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Despite the many benefits of geothermal, Canada is the only “Pacific Ring of Fire” country that doesn’t use it for commercial-scale energy. According to Desmog Blog, “New Zealand, Indonesia, the Philippines, the United States and Mexico all have commercial geothermal plants.” Iceland heats up to 90 per cent of its homes, and supplies 25 per cent of its electricity, with geothermal.

Geothermal energy is generated by heat from Earth’s rocks, liquids and steam. It can come from shallow ground, where the temperature is a steady 10 to 16 C, hot water and rocks deeper in the ground, or possibly very hot molten rock (magma) deep below Earth’s surface. As with clean-energy sources like solar, geothermal energy systems vary, from those that use hot water from the ground directly to heat buildings, greenhouses and water, to those that pump underground hot water or steam to drive turbines. The David Suzuki Foundation’s Vancouver and Montreal offices use geothermal.

According to National Geographic, geothermal power plants use three methods to produce electricity: dry steam, flash steam and binary cycle. Dry steam uses steam from fractures in the ground. “Flash plants pull deep, high-pressure hot water into cooler, low-pressure water,” which creates steam. In binary plants, which produce no greenhouse gas emissions and will likely become dominant, “hot water is passed by a secondary fluid with a much lower boiling point,” which turns the secondary fluid into vapour.

Unlike wind and solar, geothermal provides steady energy and can serve as a more cost-effective and less environmentally damaging form of baseload power than fossil fuels or nuclear. It’s not entirely without environmental impacts, but most are minor and can be overcome with good planning and siting. Geothermal fluids can contain gases and heavy metals, but most new systems recycle them back into the ground. Operations should also be located to avoid mixing geothermal liquids with groundwater and to eliminate impacts on nearby natural features like hot springs. Some geothermal plants can produce small amounts of CO2, but binary systems are emissions-free. In some cases, resources that provide heat can become depleted over time.

Although geothermal potential has been constrained by the need to locate operations in areas with high volcanic activity, geysers or hot springs, new developments are making it more widely viable. One controversial method being tested is similar to “fracking” for oil and gas. Water is injected into a well with enough pressure to break rock and release heat to produce hot water and steam to generate power through a turbine or binary system.

Researchers have also been studying urban “heat islands” as sources of geothermal energy. Urban areas are warmer than their rural surroundings, both above and below ground, because of the effects of buildings, basements and sewage and water systems. Geothermal pumps could make the underground energy available to heat buildings in winter and cool them in summer.

New methods of getting energy from the ground could also give geothermal a boost. Entrepreneur Manoj Bhargava is working with researchers to bring heat to the surface using graphene cords rather than steam or hot water. Graphene is stronger than steel and conducts heat well. Bhargava says the technology would be simple to develop and could be integrated with existing power grids.

Unfortunately, geothermal hasn’t received the same level of government support as other sources of energy, including fossil fuels and nuclear. That’s partly because upfront costs are high and, as with oil and gas exploration, geothermal sources aren’t always located where developers hope they’ll be. As Desmog notes, resources are often found in areas that already have access to inexpensive hydro power.

Rapid advancements in renewable-energy and power-grid technologies could put the world on track to a mix of clean sources fairly quickly — which is absolutely necessary to curtail global warming. Geothermal energy should be part of that mix.

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14 Comments

Mar 14, 2017 9:11 AM

James says...

Ground source heat pumps can virtually extinguish underfloor heating costs. Heat pumps are becoming suitable for all purposes and situations. The water heat pump similar to the ground source heat pump is able to recover heat from rivers and the ocean. Indoor heat pumps are a significant advancement allowing application in commercial and domestic sectors. See our website for more details: http://www.geyserenergy.co.uk

Sep 16, 201611:28 PM

Mary Anne Causyn says...

Yes. I think the point is that in different places, different methods of power generation will be more suitable. So electricity production would become a regional or local concern, I guess. A lot of new, perhaps smaller infrastructure. Not just expensive, but a lot of thinking and leg-work required.

Jul 31, 2016 9:02 PM

emma jack says...

Low prices and high efficiency make portable air conditioners and window air conditioners inexpensive room air conditioner alternatives to central air for cooling one or two rooms

Jun 27, 2016 5:48 AM

Susan Khan says...

Can we not get the government to invest more in Geothermal Energy.
The price of Hydro is high, Why is the government not promoting more solar use in homes, we don’t see enough in promoting solar use and making it more affordable for homeowners to install.

Apr 09, 2016 4:53 PM

Sam North says...

I was wondering if your following Andrea Rossi and his E cat LENR technology.There is a big debate going on in the LENR community
with one side saying fraud the other thinks it’s for real.
Ecat world and Ego out are two blogs that follow it.

A minor point, but Todd De Ryck, does it matter if it is scalable or available everywhere? Is not the correct question ‘does it work here?’
The valley in which I live is totally calm, so any sort of wind turbine would be useless. Does that negate the use of wind power on the eastern slope of the Rockies, where people fall over on a calm day?
Perhaps local solutions are more appropriate in this era.

Apr 03, 2016 7:23 AM

Paul says...

Is it possible that the earths core will freeze because of this! Its like leaving the window open at night. Bruce Willis is getting too old for this! I’m not sure that less expensive actor is up to the task either.

Apr 02, 2016 1:40 PM

Alison Thompson says...

Would you like more info on Canadian geothermal power and heat opportunities? Please visit the Canadian Geothermal Energy Associations’ website: www.cangea.ca

Apr 02, 2016 7:29 AM

Irene says...

Geothermal energy is as frightening to me as nuclear energy. Fracking for oil has caused excessive harm to the environment. What makes geothermal energy fracking any different? If only small amounts of the alternate fluid used in this process gets into lakes it can be devastating to all aquatic life. After looking into the purchase of geothermal heat pumps for my home, on a lake, I nixed the idea, in favour of a healthy environment.

Apr 01, 2016 3:50 PM

Ian Crawford says...

Thank you David for highlighting geothermal energy. For more information go to our website at: http://www.geothermal.org/

Apr 01, 2016 2:29 PM

Alex V. Tardecilla says...

Thank you, sir for posting your thoughts on the potential of geothermal energy to produce electricity here in our native land of Canada. As a professional who has worked in the oil and gas industry in the last 10 years, I have decided to switch to renewable energy, specifically to geothermal — for my two daughters and their future children.
Regards,
Alex V. Tardecilla

Apr 01, 2016 2:20 PM

Zig says...

Geothermal is great in the right place.
So it is not the best solution for every location. For the average house, only if the heating load and cooling load is close 50% then it is not a bad solution. But if the ground is too cold and the geology is not a very good heat conductor the geothermal will use huge amounts of power to run the compressor. The geology in Iceland is a lot different and conducive to geothermal because of the high temperatures in the ground.

Apr 01, 2016 9:17 AM

Todd De Ryck says...

It would be a good idea to include some data, for example, is geothermal scalable at the global level required, how much global electricity does it provide today, is it available everywhere? IEA electricity generation data http://www.iea.org/media/statistics/surveys/electricity/mes.pdf A couple of links to provide more details https://blog.udemy.com/geothermal-energy-pros-and-cons/ and http://www.c2es.org/technology/factsheet/geothermal . California may be a good location in USA, untapped, which would be good since it is essentially a natural gas state (note change from 2011 to 2012) http://energyalmanac.ca.gov/electricity/electricgenerationcapacity.html

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